If you're logging in extra hours at work, you could be doing yourself more harm than good, according to a new study.

Studies are increasingly finding that clocking in too many hours can actually be self-defeating due to the effects overworking has on Americans’ sleep patterns. Harvard Medical School researchers have estimated that insomnia plagues nearly a quarter of the United States workforce, costing businesses $2,280 a year per worker for a total annual loss of $63 billion for the overall economy.

The Harvard researchers are not alone in their worries: In the past decade the Centers for Disease Control found 23.2 percent of U.S. adults reported lack of concentration because of too little sleep, and 8.6 percent acknowledged it hurt their job performance.

A sleep-deprived worker can be just as unproductive as a worker who has consumed some alcohol, Harvard sleep researcher Russell Sanna recently told NPR's Marketplace.

Marketplace recounted how Omaha, Nebraska credit union president Gail DeBoer finally linked the chronic headaches she suffered from to the work email she was checking early in the morning. DeBoer also realized her workers were exhausted trying to follow her example. To remedy the situation, she "[got] rid of smartphones for everyone except her senior team [and] also trained herself not to check email before bed," Marketplace reported.

So how does working less and sleeping more improve productivity? Well-rested people make up for their sleep and breaks with intense periods of productive work that are much more efficient than the increasingly unproductive work of the tired people through the day, Tony Schwartz of The Energy Project explains in a Harvard Business Review blog.

It might be best to encourage the behavior of the rested worker in Schwartz's post, who took a 15-minute break after 90 minutes of work, grabbed a 45-minute lunch or gym workout away from the desk, a quick 20-minute nap around 3 p.m. and a short walk around 4:30 p.m.

“It’s not just the number of hours we sit at a desk that determines the value we generate,” Schwartz writes. “It’s the energy we bring to the hours we work. Human beings are designed to pulse rhythmically between spending and renewing energy.”